Look around for my past posts on anal sex. There is no way the anus can be repeatedly penetrated without damage. I am aware that this is a common practice among heterosexual partners and, more especially, homosexual males. My rants are not to try to talk people out of the practice but to make them aware of potential problems thirty years from now.

My recommendation is nothing hard (as in plastic, glass, metal) until you have it looked and examined properly.